DE102019135681B4 - energy storage - Google Patents

Abstract

Energy storage device which is preferably at least partially sunk into the ground, comprising a water heat exchanger (18) and an air heat exchanger (14) arranged above the water heat exchanger (18), the water heat exchanger (18) being arranged in a liquid reservoir (24) which is on a bottom (26) is formed between an inner wall (36) and an outer wall (38), the inner wall (36) enclosing a cavity which is at least partially filled by at least a first container (30) and a second container (32), wherein the first container (30) and the second container (32) have equal volumes and each form a pole of a redox flow battery.

Description

The invention relates to an energy store which is preferably at least partially embedded in the ground.

The use of fossil fuels is not only increasingly uneconomical, but is also increasingly being questioned due to the associated negative effects on the climate. In addition to an increase in the use of regenerative energy sources, efficient systems for energy storage are therefore also required, which, in combination with intelligent controls, can ensure reduced energy consumption, for example when heating or cooling buildings or systems. Due to such measures, a high savings potential can be created regardless of the energy source used, which also absorbs the associated installation costs.

From the DE 29 26 610 A1 a memory for providing the input thermal energy at a low temperature level for heat pump systems is known, which absorb this energy and release it again at a higher temperature level. A pool of water is designed in such a way that its water content can freeze without damaging the pool and that a heat exchanger system located on the pool floor or embedded in the pool floor allows the cooling and freezing heat of this pool to be fed to the cold side of a heat pump.

In addition to using an artificial water basin, it is also known to use natural bodies of water as a storage medium. That's it DE 10 2015 104 909 B3 an energy storage device is known which has a heat exchanger which is arranged floating on a lower reservoir designed as a lake, which can preferably be filled with water via a first supply line, with water from the lower reservoir being supplied via a second supply line and coolant penetrating the heat exchanger via a third supply line of a heat pump in separate circuits can be fed, so that energy can be removed via the heat exchanger with icing of the water in the lower basin or in the form of sensible heat from the water in the lower basin and can be passed on to a consumer for heat output and/or cold output.

Furthermore, from the DE 10 2015 121 177 A1 a floating device for introducing thermal energy into a body of water and for extracting thermal energy from the body of water is known, which has a water heat exchanger which, after the device has been inserted, is immersed in the body of water and has an inlet and an outlet for a heat transfer fluid that contains heat energy give off to the water body or extract thermal energy from the body of water. The device also has an air heat exchanger, which can be penetrated by ambient air and also has an inlet for water originating from the body of water with a corresponding outlet, so that water can flow from the body of water through the air heat exchanger, with thermal energy between the air heat exchanger ambient air flowing through and the water flowing through the air heat exchanger.

Post-published US 2020/0 166 290 A1 shows a thermal energy storage device. It includes a thermal vector unit and a thermal accumulator unit. The thermo-vector unit includes one or more flow channels for a working fluid. The thermal-accumulator unit includes a thermal storage material configured to operate in a heat exchange relationship with the working fluid and to store and release thermal energy due to heat exchange with the working fluid.

the DE 10 2012 101 541 A1 shows a ground-based heat accumulator having a bottom surface, a top surface and a wall surface. At least the wall surface has a plurality of individual wall segments and at least one heat exchanger is provided within the heat accumulator. Under operating conditions, the heat accumulator has a solid filling. One or more wall segments each have at least one heat exchanger.

The devices described above usually interact with a heat pump installed in a building. This can be supplied with electrical energy, for example, via the power grid or your own power storage unit.

Based on this prior art, the inventors have now set themselves the task of creating an improved energy store that can work together with other energy sources without increasing the installation effort.

This object is solved by the features of patent claim 1. Further advantageous configurations of the invention are the subject matter of the dependent claims. These can be combined with one another in a technologically sensible manner. The description, in particular in connection with the drawing, additionally characterizes and specifies the invention.

According to the invention, an energy storage device, which is preferably at least partially buried in soil, is provided, comprising a water heat exchanger and an air heat exchanger arranged above the water heat exchanger, the water heat exchanger being arranged in a liquid reservoir formed on a floor between an inner wall and an outer wall , The inner wall enclosing a cavity which is at least partially filled by at least a first container and a second container, the first container and the second container having equal volumes and each forming a pole of a redox flow battery.

According to the invention, the cavity located inside an energy store is used to accommodate a redox flow battery there, which is formed from the first container and the second container. For this purpose, the two containers have the same volume, so that both poles can be provided with the same energy content. The energy store is a device in which both an air heat exchanger and a water heat exchanger are arranged one on top of the other. This makes it possible to both store and transmit energy. The two heat exchangers work together with heat pumps, so that the energy storage can deliver heat to a building or cool it. For this purpose, the water heat exchanger has a liquid reservoir that is typically filled with water. In the liquid reservoir, a large number of spirally laid pipes are usually arranged, which are filled with the working fluid of the heat pump. In order to save costs and weight, the tubes of the water heat exchanger are manufactured as plastic tubes. The air heat exchanger, through which air from the environment flows, is usually made of metal and has several blocks with metal fins, which are also connected to one another so that the working fluid of the heat pump flows through them in turn. Since no arbitrarily small bending radii can be produced from prefabricated plastic pipes, there is free space inside the liquid reservoir that is not covered by pipes and is therefore not connected to the heat pump. According to the invention, this unused area is left out in the form of the cavity, so that it can be subjected to further use as a redox flow battery. It is therefore possible to store or transmit both thermal energy and electrical energy in the energy store according to the invention. In a building that is heated or cooled by means of the heat exchanger described above, this makes it possible to store additional electrical energy in the two containers, for example from a solar system or a wind turbine, and to transfer it to the building if necessary. Use in connection with the operation of the heat pump(s) or their control is also conceivable.

According to one embodiment of the invention, the cavity extends beyond the water heat exchanger to an underside of the air heat exchanger.

The area between the water heat exchanger and the air heat exchanger is usually provided with an insulation layer, which is not required in the area of the two containers, since there is no liquid reservoir here that would have to be insulated. Accordingly, this area can also be used for the redox flow battery, so that a higher memory content can be achieved.

According to a further embodiment of the invention, the first container encloses the second container on the peripheral side.

Consequently, the first container is arranged around the second container, whereby the two containers can have the same heights, but whose lateral dimensions are chosen in such a way that the volumes are equal overall. It has been found that such an embodiment is mechanically very stable, which has particular advantages when filling the redox flow battery. In other embodiments, however, the two containers can also be arranged one above the other, which could also simplify the production of the containers, since these could be manufactured identically for both containers, for example.

According to a further embodiment of the invention, the energy storage device has a third container, which is preferably designed as a hot water storage device.

In particular for the hot water supply as drinking water or process water, the provision of a further hot water storage tank can be advantageous, which is intended to supply the building and can be fed, for example, via a solar thermal system. However, such a hot water storage tank is not connected to the air-conditioning supply units of the energy storage tank, so that its contents can be used as drinking water in a hygienically safe manner.

According to a further embodiment of the invention, the third container is together with the first container and second container arranged in the cavity.

The region of the cavity can be used to arrange the third container, which is typically designed as a hot water storage tank, which on the one hand enables a simple structure, but on the other hand limits the volume and thus usable storage capacity for the redox flow battery.

According to a further embodiment of the invention, the third container is arranged below the cavity, separated from the first container and the second container, in a further, preferably isolated cavity.

In another embodiment, the third container is arranged below the cavity, preferably also below the energy store beyond the cavity. In this way, the volume of the redox flow battery is not restricted, while at the same time the storage of hot water can be improved by means of insulation from the environment.

According to a further embodiment of the invention, the inner wall is in the form of a circular cylinder.

Such energy stores are typically of circular design, so that both the inner wall and the outer wall have a circular-cylindrical shape. Accordingly, the liquid reservoir has a cross-sectional area in the form of a circular ring, in the interior of which the cavity is formed, which thus also has a circular-cylindrical shape. The two containers can then likewise be designed with cross-sectional areas in the form of an annulus or a circle.

According to a further embodiment of the invention, the inner wall is made of a plastic material which is fixed to a framework, further struts being arranged in the cavity, which support the first container and the second container.

A weight-saving design with a framework is proposed for the energy store, with the liquid reservoir of the water store being sunk into the ground on the outer wall. Any compressive forces are therefore absorbed outwards by the soil. Towards the inner wall, these compressive forces are absorbed by the stud frame. Additional struts stabilize the two containers so that they are held securely inside the energy storage device. The overall result is a mechanically stable structure that can also be produced easily and inexpensively from plastic materials or metal profiles, with a large part of the components being able to be prefabricated, which results in a further reduction in production costs.

According to a further embodiment of the invention, the first container and the second container are designed in such a way that a supply channel remains free when they are arranged in the cavity.

Accordingly, both the redox flow battery and the hot water tank that may be present in the third tank can be supplied via the supply duct. When the two containers are arranged one above the other, the supply channel can be formed, for example, on the outer circumference, with other configurations also being possible. If the two containers are designed to lie side by side, the supply channel can also be guided axially along a longitudinal axis in the center of the container.

• 1 eine perspektivische Seitenansicht eines erfindungsgemäßen Energiespeichers,
• 2 der Energiespeicher aus 1 in einer geschnittenen Darstellung entlang eines Segments,
• 3 einen Schnitt durch den Energiespeicher aus 1 in einer Seitenansicht,
• 4 Bestandteile einer weiteren Ausführungsform des erfindungsgemäßen Energiespeichers in einer perspektivischen Seitenansicht,
• 5A die Anordnung aus 4 in einer Seitenansicht,
• 5B einen Schnitt durch die Anordnung aus 4 in einer Seitenansicht,
• 6A Bestandteile einer weiteren Ausführungsform des erfindungsgemäßen Energiespeichers in einer perspektivischen Seitenansicht,
• 6B einen Schnitt durch die Anordnung aus 6A in einer Seitenansicht,
• 7A Bestandteile einer weiteren Ausführungsform des erfindungsgemäßen Energiespeichers in einer perspektivischen Seitenansicht,
• 7B einen Schnitt durch die Anordnung aus 7A in einer Seitenansicht, und
• 8 Bestandteile einer weiteren Ausführungsform des erfindungsgemäßen Energiespeichers in einer perspektivischen Seitenansicht.

Some exemplary embodiments are explained in more detail below with reference to the drawing. Show it:

• 1 a perspective side view of an energy store according to the invention,
• 2 the energy storage 1 in a sectional representation along a segment,
• 3 a section through the energy storage device 1 in a side view,
• 4 Components of a further embodiment of the energy store according to the invention in a perspective side view,
• 5A the arrangement 4 in a side view,
• 5B cut through the arrangement 4 in a side view,
• 6A Components of a further embodiment of the energy store according to the invention in a perspective side view,
• 6B cut through the arrangement 6A in a side view,
• 7A Components of a further embodiment of the energy store according to the invention in a perspective side view,
• 7B cut through the arrangement 7A in a side view, and
• 8th Components of a further embodiment of the energy store according to the invention in a perspective side view.

In the figures, identical or functionally identical components are provided with the same reference symbols.

With reference to 1 a first embodiment of an energy store 2 according to the invention is described below. In 1 the energy store 2 according to the invention is shown in a perspective side view, the energy store 2 comprising an outer shell 4 which has a substantially cylindrical shape in the example shown. A connection box 6 is arranged on the outer shell 4, to which feed lines and discharge lines can be connected, which lead to one or more heat pumps which are arranged, for example, in a building. Furthermore, a flow of working fluid is also passed on to an air heat exchanger and a water heat exchanger inside the energy store 2 via the connection box 6 .

On its upper side, the energy store 2 has a cover 8 which is provided approximately in the center with a plurality of exhaust air slots 10 through which ambient air sucked in via a peripheral air supply slot 12 on the cover 8 can escape. The energy store 2 is usually partially buried in the ground, with the air inlet slot 12 protruding above the ground. The soil therefore does not completely cover the outer shell 4, with at least the terminal box 6 typically still being covered.

In 2 the energy store 2 is shown in a partially sectioned representation, the details of the heat exchangers having been omitted for the sake of simplicity, since these are not part of the invention. In the case of energy storage device 2, in an upper area, which is in 2 hatched and denoted by reference numeral 14 , an air heat exchanger is arranged, through which ambient air flows from the inlet air slot 12 . The air flow is directed to the exhaust air slots 10 via a fan 16 arranged inside.

Furthermore, in the energy store in a lower area, which is in 2 is also shown hatched and is denoted by the reference numeral 18, a water heat exchanger is provided, in which a liquid reservoir is formed between an inner wall and an outer wall. The inner wall and the outer wall can be made of plastic, for example, and are inserted into a framework, with a circumferential upper inner ring 20 and a circumferential upper outer ring 22 of the framework forming the upper end of the liquid reservoir 24 . The liquid reservoir 24 is delimited at the bottom by a floor 26 . The water heat exchanger is delimited by a cover plate 28 towards the air heat exchanger.

The liquid reservoir 24 encloses a cavity into which a first container 30 and a second container 32 are placed. The first container 30 thereby encloses the second container 32, the first container having a substantially circular annular cross-sectional area, while the second container 32 is formed with a circular cross-sectional area. The height of the first container 30 and the second container 32 can protrude beyond the upper edge of the liquid reservoir 24 in the direction of the air heat exchanger, with the area on the side of the first container 30 above the liquid reservoir 24 being typically at least partially filled by an insulation layer during operation of the energy store 2 will. The first container 30 and the second container 32 have the same volume and each act as a liquid reservoir for one pole of a redox flow battery.

In 3 the energy store 2 is shown again in a sectional view, the sectional plane being arranged approximately centrally along the longitudinal axis of the energy store 2 . It can be seen that in the shaded area 18 the liquid reservoir is delimited by an inner wall 36 and an outer wall 38 which, together with the base 26, form the delimitation of the liquid reservoir 24. The inner wall 36, the outer wall 38 and the base 26 can be formed in one piece or assembled from several components, for example welded. Typically, the inner wall 36, outer wall 38 and floor 26 use sheets of plastic material.

In 4 Another perspective side view is shown, in which all other parts of the energy store 2 have been removed except for the stand 40 and the first container 30 and the second container 32 for the purpose of better representation. It can be seen that the first container 30 and the second container 32 are surrounded by a plurality of struts 42 which provide support for the first container 30 and the second container 32 so that they are arranged in a mechanically stable manner inside the energy store 2 . The framework 40 also includes a peripheral lower outer ring 44 which is connected to the area below the first container 30 and the second container 32 by means of a plurality of ground braces 46 . A plurality of vertical side braces 48 connect the lower outer ring 44 to the upper one Outer ring 22. The upper outer ring 22 is connected to the upper inner ring 20 via a plurality of intermediate struts 50. This results in a stable construction of the framework 40, which can accommodate the different components of the energy store 2.

In 5A the stand 40 is shown again in a side view. It can be seen that the struts 42 extend beyond the upper outer ring 22, with their upper ends shaped to receive the cover plate 28, so that in addition to mechanically supporting the first container 30 and the second container 32, some of the weight of the Air heat exchanger on the struts 42 rests.

In 5B the stand 40 is shown again in a sectional view along the plane AA'. As already mentioned above, the first container 30 and the second container 32 have the same volumes.

In 6A a further embodiment of an energy store is shown in a perspective side view, in which the first container 30 is again arranged with a circular cross-section around the cylindrical second container 32 . In order to be able to feed through a first supply line 60 and a second supply line 62, a supply channel 64 is formed along the centrally arranged longitudinal axis of the second container 32, through which the first supply line 60 and the second supply line 62 are routed.

In 6B this is shown again in a sectional view, with the first supply line 60 and the second supply line 62 being omitted for the sake of simplicity. It can be seen that the supply channel 64 runs inside the second container 32 . The dimensions of the first container 30 and the second container 32 are adjusted accordingly in order to be able to compensate for the volume loss of the second container 32 in the area of the supply channel 64 . This embodiment is particularly advantageous when it is combined with a third container that requires the first supply line 60 and the second supply line 62 .

Such an implementation is in 7A in a perspective side view and in 7B shown in an associated sectional view. The third container 72 is located behind a further outer shell 70 and can be connected to the first supply line 60 and the second supply line 62 via the supply channel 64 . The third tank 72 is, for example, a hot water tank that can be used to supply drinking water or service water to a building.

In order to protect the third container 72 against temperature losses to the environment, it is embedded in an insulating material 74, with an intermediate plate 76 being introduced between the first container 30 and the second container 32, which ensures mechanical stability. The structure rests on a further base plate 78. Such a structure can now, as already shown above, be arranged in the cavity of the liquid reservoir 24. Typically, the first container 30 and the second container 32 will each hold about 350 liters of liquid, while the third container 72 has a capacity of about 200 liters. However, the numerical values are only to be understood as an example in order to give an approximate indication of the order of magnitude.

In other embodiments, it would also be possible to expand the third container 72 radially so far that it comes to lie below the liquid reservoir 24 and the liquid reservoir 24 completely covers the third container 72 designed as a hot water tank or even goes beyond it. In the 7A and 7B However, the embodiment shown represents a very compact structure in which different forms of energy can be stored and transmitted in a simple manner.

In 8th a further embodiment of the energy store is shown. In contrast to the previous embodiments, here the first container 30 and the second container 32 are arranged one above the other. Furthermore, the stand 40 has been expanded to include additional intermediate rings 80 . In the area of cavity 82, space can remain free for a third container, as in 8th is shown, or the cavity 82 can be completely filled with the first container 30 and the second container 32 .

The features specified above and in the claims, as well as the features that can be inferred from the illustrations, can be advantageously implemented both individually and in various combinations. The invention is not limited to the exemplary embodiments described, but can be modified in many ways within the scope of specialist knowledge.

Reference List

2

energy storage

4

outer shell

6

closing box

8th

end cap

10

exhaust vents

12

supply air slot

14

air heat exchanger

16

fan

18

water heat exchanger

20

upper inner ring

22

upper outer ring

24

fluid reservoir

26

floor

28

cover plate

30

first container

32

second container

36

inner wall

38

outer wall

40

stud frame

42

striving

44

lower outer ring

46

ground braces

48

side braces

50

intermediate braces

60

first supply line

62

second supply line

64

supply channel

70

more outer shell

72

container

74

insulation material

76

intermediate plate

78

another base plate

80

intermediate rings

82

cavity

Claims (10)

Energy storage device which is preferably at least partially sunk into the ground, comprising a water heat exchanger (18) and an air heat exchanger (14) arranged above the water heat exchanger (18), the water heat exchanger (18) being arranged in a liquid reservoir (24) which is on a bottom (26) is formed between an inner wall (36) and an outer wall (38), the inner wall (36) enclosing a cavity which is at least partially filled by at least a first container (30) and a second container (32), wherein the first container (30) and the second container (32) have equal volumes and each form a pole of a redox flow battery. energy storage after claim 1 , in which the cavity extends beyond the water heat exchanger (18) to an underside of the air heat exchanger (14). energy storage after claim 1 or 2 In which the first container (30) encloses the second container (32) on the circumference. energy storage after claim 1 or 2 wherein the first container (30) is arranged above the second container (32). Energy storage according to one of Claims 1 until 4 Having a third container (72), which is preferably designed as a hot water tank. energy storage after claim 5 wherein the third container (72) is arranged in the cavity together with the first container (30) and second container (32). energy storage after claim 5 , in which the third container (72) is arranged below the cavity separately from the first container (30) and second container (32) in a further, preferably isolated cavity. Energy storage according to one of Claims 1 until 7 , in which the inner wall (36) is designed in the form of a circular cylinder. Energy storage according to one of Claims 1 until 8th wherein the inner wall (36) is made of a plastic material which is fixed to a stud frame (40), further struts (42) being arranged in the cavity, which support the first container (30) and the second container (32). . Energy storage according to one of Claims 1 until 9 , in which the first container (30) and the second container (32) are designed in such a way that a supply channel (64) remains free when they are arranged in the cavity.

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